1. Field of the Invention
The present invention relates to a transmission assembly with a lock gate structure for an optical disc device to prevent pieces of an optical disc from flying out of the optical disc device, and more particularly to an optical disc device provided with a transmission assembly to control movement of the lock gate structure so as to open or close the loading slot of the optical disc device.
2. Description of the Related Art
A conventional slot-in optical disc device, such as DVD-ROM, VCD-ROM, CD-ROM and onboard audio system, is provided with a sensor to automatically detect insertion of an optical disc in the loading slot and start the conveying mechanism.
The conventional slot-in optical disc device does not have a carry tray to carry the optical disc. When the information in the optical disc is being read in the working area, the optical disc is rotated at very high speed, so the optical disc may be fly out of the loading slot during operational process. Sometimes, defected material for making the optical disc may cause the optical disk to break when the optical disc is rotated at high speed and thus the pieces from the broken optical disk may escape from the loading slot of the optical disc device. This slot-in optical disc device is not provided with a cover structure that can open or close the loading slot so a user operating this type of optical disc device might be in danger.
Nowadays there are two main types of optical discs, i.e. 8-cm diameter disc and 12-diameter disc, but the slot-in optical disc device is usually designed for 12-cm diameter disc, not for 8-cm diameter disc. According to public technical literatures, it is known that through detecting the loading of the disc by optical sensors or two pairs of optical interceptors, the optical disc device is able to determine whether the disc is an 8-cm diameter disc or a 12-cm diameter disc. The device then is able to control a clamping/conveying device to hold and convey the optical disc according to different types of discs. There is another type of slot-in optical disc device having the similar structure as that mentioned above, but the principle of the technology is based on the time difference with which discs of different dimensions pass over the optical sensors. Furthermore, there is another different technology disclosed to determine the dimension of the disc passing through the optical sensor, which is related to the technology of the present invention. However, detailed description thereof is not going to be addressed hereinafter for brevity.
Seeing that there are such disadvantages in the open/close disc-conveying mechanism, the open/close loading slot mechanism and the adaptability for 12-cm diameter disc or 8-cm diameter disc in the conventional optical disc device, the present invention aims to resolve above problems and improve the conventional optical disc device.